Method of mounting electronic circuit chip

ABSTRACT

In a method of mounting a planar electronic circuit chip onto a flexible sheet together with another planar electronic element, the electronic circuit part and the another electric element are selected so that the planar surface of the another electric element is greater than the planar surface of the electronic circuit chip, and the another electric element and the electronic circuit chip are mounted on the sheet so that the planar surface of the another electric element and the planar surface of the electronic circuit chip are in parallel with the sheet surface, and the planer surface of the electronic circuit chip is accommodated within the planar surface of the another electric element as viewed in a direction perpendicular to the sheet surface.

TECHNICAL FIELD

[0001] The present invention relates to a technology of mounting anelectronic circuit chip such as an integrated circuit chip onto a softmaterial such as paper.

TECHNICAL BACKGROUND

[0002] These years, electronic circuit chips such as integrated circuitchips have become thinner and thinner, and accordingly, the electroniccircuit chips have been used in various configurations.

[0003] In a use condition of such an electronic circuit chip, forexample, as disclosed in Japanese Laid-Open Patent No. H3-38396, asmall-sized electronic circuit chip for storing data is embedded in aportable plastic card together with an element for reading data in anoncontact manner. For example, such a plastic card that personalidentification data has been previously stored in the electronic circuitchip, can be used as an electronic ID card which can confirm personalidentification data in a noncontact manner.

DISCLOSURE OF INVENTION

[0004] The use configuration of the above-mentioned electronic circuitchip have become prosperous. However, conventionally, materials to whichelectronic circuit chips are mounted have been limited to materials suchas plastic cards which are hard so that it cannot be largely bent andfolded. It is because if a force which can largely bend or fold thematerials is exerted to the materials, the electronic circuit chips arepossibly damaged due to the reason of strength thereof.

[0005] However, if an electronic circuit chip can be mounted to amaterial such as paper which can be largely bent or folded, the useconfiguration of the electronic circuit chip can be broadened, andhigher convenience becomes available for people.

[0006] Accordingly, an object of the present invention is to provide amounting method with which an electronic circuit chip is prevented frombeing damaged even though a soft material on which the electroniccircuit chip is mounted is bent or folded.

[0007] Further, another object of the present invention is to provide anelectronic circuit chip which cannot be damaged even through a softmaterial such as paper on which the electronic circuit chip is mountedis bent or folded.

[0008] To the end, according to the present invention, there is provideda method of mounting an electronic circuit chip onto a foldable sheet,wherein during mounting, the electronic circuit chip is prevented frombeing located at a position where the sheet creates a crease when it isfolded in a predetermined folding manner. With this mounting method, theelectronic circuit chip is located while it is avoided from beingmounted at a position of a crease to which a high moment force isexerted upon folding of the sheet, thereby it is possible to prevent theelectronic circuit chip from being damaged by folding the sheet.

[0009] Further, with the use of parameters required for an electroniccircuit chip to be mounted on the above-mentioned sheet, a specificationfor the electronic circuit chip, which can prevent occurrence of damageto the electronic chip even though the sheet is folded, is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a circuit diagram illustrating a circuit using anelectronic circuit chip which is mounted on paper in an embodiment ofthe present invention;

[0011]FIGS. 2a and 2 b are views illustrating such a condition that acircuit using an electronic circuit chip in a first embodiment of thepresent invention is mounted on paper;

[0012]FIGS. 3a and 3 b are views illustrating a such condition that acircuit using an electronic circuit chip is mounted on paper in a secondembodiment of the present invention;

[0013]FIGS. 4a to 4 d are sectional views illustrating such conditionsthat an electronic circuit chip are mounted on paper in a thirdembodiment of the present invention;

[0014]FIG. 5 is a view which approximately exhibits a force and a momentexerted so as to curve the electronic circuit chip in the thirdembodiment of the present invention, and

[0015]FIG. 6 is a view illustrating a tape on which electronic circuitchips are mounted.

BEST MODE FOR CARRYING OUT THE INVENTION

[0016] Explanation will be made hereinbelow of embodiments of thepresent invention.

[0017] In the following explanation of the embodiments according to thepresent invention, there is exemplified in such a configuration that anelectronic circuit chip for storing data is mounted on a paper togetherwith an element for reading the data from the electronic circuit chip ina noncontact manner. However, it is noted that an electronic circuitchip to be mounted may be any of those other than that mentioned above,and further, any of soft materials other paper on which the electroniccircuit chip is mounted may be used if it may be largely bent or it maybe folded.

[0018] Further, a thin and laterally very long sheet such a tape may beused other than a planer material. That is, it may be the one which canbe rolled up.

[0019] Explanation will be made of a first embodiment of the presentinvention.

[0020] Referring to FIG. 1 which shows a circuit composed of anelectronic circuit chip adapted to be mounted on a paper in thisembodiment, and an element for reading data from the electronic circuitchip in a noncontact manner, there is shown an electronic circuit chip 1in which electronic circuits are integrated on a silicon chip. Further,elements, that is, a capacitor 2 and an antenna 3 are elements forreading data from the electronic circuit chip 1 in a noncontact manner.

[0021] When an electromagnetic wave is applied to the above-mentionedcircuit from the outside, the electromagnetic wave induces a currentrunning through the capacitor through the antenna 3, and a power ischarged in the capacitor 2. Further, the power charged in the capacitorcauses the electronic circuit 1 to be energized so that data previouslystored is transmitted in the form of an electromagnetic wave from theantenna 3. Accordingly, through the application of an electromagneticwave, the data stored in the electronic circuit chip can be read on theoutside thereof in a noncontact manner.

[0022]FIG. 2a shows a condition in which the circuit is mounted onpaper, reference numeral 200 denotes the outer surface of a sheet onwhich the circuit is mounted. In the figure, reference numerals 210 a to210 d denote configuration examples of the circuits which are mounted ona paper sheet.

[0023] It is noted here that the circuit 210 d is bonded so as to beheld between two sheets 400, 401 (201, 203) or a circuit 210 d is bondedto a rear surface of a paper sheet 500.

[0024] Further, the circuit is mounted on the paper sheet in such aconfiguration that the electronic circuit chip is prevented from beingmounted at a position on a crease which is created in the paper sheet,as indicated by a one-dot chain line, and a two-dot chain line in thetop view 200, when the paper sheet is folded. This figure shows such anexample that the paper sheet is possibly folded into ½, ⅓ or ¼ in thelateral direction thereof, and is possibly folded into ½ or ¼ in thelongitudinal direction. The one-dot chain lines and the two-dot chainlines in the figure exhibit creases when the paper sheet is folded asmentioned above.

[0025] A position where a crease is possibly created so that theelectronic circuit chip 1 is not located, is a position in accordancewith a configuration of folding if the configuration of folding has beenpreviously known. Further, if no configuration with which the paper isfolded are previously known, a position which is one or a plurality ofconfigurations which are usually used in various paper folding methodsin accordance with kinds or uses of the paper sheet. That is, ingeneral, the position may be on a crease which is created at any ofpositions obtained by 1/n of the length of the paper sheet, where n isan integer, that is, in general 2, 3, 4, 5, 6, 8, 16 in both verticaland horizontal directions, that is, positions which are ½, ⅓, ¼, ⅙, ⅛,{fraction (1/16)} of the length of the paper sheet in each of thelongitudinal and lateral directions, where a crease is possibly created,except a special kind or use of the paper sheet.

[0026] By locating the electronic circuit chip on the paper sheet, otherthan a position where a crease is created and where a large moment forceis exerted when the paper sheet is folded, it is possible to prevent theelectronic circuit chip 1 from being damaged when the paper sheet isfolded.

[0027] It is noted that the circuit 210 a is arranged so that theelectronic circuit chip 1 is located at a position in the vicinity of anedge of the paper sheet. Usually, since no large force is exerted to aposition in the vicinity of an edge of the paper sheet, a degree of theforce exerted to the electronic circuit chip 1 and the frequency of theexertion of the force to the electronic circuit chip 1 can be expectedto be less. Alternatively, in such a case that concavities andconvexities are impressed to the paper sheet for blind persons so thathard parts are formed, the electronic circuit chip 1 may be located inany of these parts since it may be expected to decrease the forceexerted to the electronic circuit chip 1 located in this part.

[0028] Further, in such a case that an antenna 3 which has a strait-linelike shape as a whole, as in this embodiment, the circuit is arranged sothat the antenna 3 is located in parallel with a side of the paper sheetas in the configuration examples 210 a to 210 d. Usually, the papersheet is bent or folded in parallel with a side of the paper sheet, andaccordingly, a degree of a force exerted to the antenna 3 and thefrequency of exertion of forces exerted to the antenna 3 can be expectedto be less.

[0029] Further, the upper bottom surface (which is a surface in parallelwith the surface) of the sheet of the electronic circuit chip 1 which isweak against a force in the bending direction, is designed so as to havea small size in order to prevent the electronic circuit chip from beingexerted thereto with a large bending moment.

[0030] Further, as shown in FIG. 2b which is an enlarged viewillustrating a circuit, the electronic circuit chip 1 is located on acapacitor 2 which is formed so that its upper bottom surface (which isin parallel with the surface of the paper sheet) is larger than theelectronic circuit chip 1, and accordingly, the upper bottom surface ofthe electronic circuit chip is accommodated within the upper bottomsurface of the capacitor 2 as viewed in a direction perpendicular to thesurface of the paper sheet. With this arrangement, the capacitor 2 canprotect the electronic circuit chip 1 from a force externally exerted.It is noted that if the upper bottom surface of the electronic circuitchip 1 is accommodated within the upper bottom surface of the capacitor2 as viewed in a direction perpendicular to the surface of the papersheet, the circuit may have such a structure that the antenna 3 islocated between the capacitor 2 and the electronic circuit chip 1.

[0031] Explanation will be hereinbelow made of a second embodiment.Refereeing to FIGS. 3a and 3 b which top views illustrating examples ofconfigurations of circuits mounted on paper sheets, and in which 310 ato 310 d exhibit examples of configurations of circuits which aremounted on the paper sheets. The circuit is held between two sheets 400,401 to which the circuit is bonded, similar to the first embodiment, asexhibited by a circuit 301 d (301, 303). Alternatively, the circuit 310d is mounted being bonded to the rear surface of a paper sheet 500.

[0032] It is noted here that in the second embodiment, the capacitor 2is manufactured, having a strength with which the capacitor cannot befolded. Further, as shown in the figures, the upper bottom surface(which is in parallel with the surface of the paper sheet) of thecapacitor is set to a size which is slightly smaller than each oflattice spaces defined by section lines (one-dot chain lines shown inthe figures) for sectioning the paper sheet in both longitudinal andlateral directions by (1/n) where n is an integer, and the sides of thepaper sheet (the shape of each grid is not always rectangular), and thecapacitor 2 is located at the center of any one of the lattice spaces.

[0033] In the example as shown, the lattice spaces are defined bysection lines (one-dot chain lines as shown in the figure) sectioningthe paper sheet into ½ in the longitudinal direction, and sectioning thepaper sheet into ¼ in the lateral direction, and the sides of the papersheet. The section lines defining the lattice spaces are set so that thecreases in a certain folding configuration become the section lines ifthis folding configuration has been previously known. Further, if nofolding configuration has not previously known, creases which arecreated in one of folding configurations which are usually used inaccordance with a kind or use of the paper sheet are set as the sectionlines. That is, other than a special kind or use of the paper sheet, thepositions of the section lines defining the lattice spaces are set atevery ½, ⅓, ¼, ⅙, ⅛ or {fraction (1/16)} of the length of the papersheet in either of the lateral and the longitudinal directions.

[0034] Further, in the second embodiment, as shown in FIG. 3b which isan enlarged view illustrating the circuit, the electronic circuit chip 1is arranged on the capacitor which is manufactured so that its upperbottom surface (which is in parallel with the surface of the papersheet) is larger than the electronic circuit chip 1, and accordingly,the upper bottom surface of the electronic circuit chip 1 isaccommodated within the upper bottom surface of the capacitor 2 asviewed in a direction perpendicular to the surface of the paper sheet.With this arrangement, the capacitor 2 can protects the electroniccircuit chip 1 against a force externally exerted. It is noted that ifthe upper bottom surface of the electronic circuit chip 1 isaccommodated within the upper bottom surface of the capacitor 2 asviewed in a direction perpendicular to the surface of the paper sheet,the circuit may have such a structure that the antenna 3 is locatedbetween the capacitor 2 and the electronic circuit chip 1.

[0035] According to the second embodiment configured as mentioned above,since the paper sheet can hardly be folded in the part occupied by thecapacitor 2, it can be expected that the paper sheet is never folded inthe part occupied by the capacitor 2. Thus, the electronic circuit chip1 located in the part occupied by the capacitor 2 can be expected to beprevented from being exerted thereto with a strong force externallyapplied. Further, the capacitor 2 is located at a position which doesnot hinder the folding of the paper sheet in a usual configuration, andaccordingly, it is possible to present the convenience of the use of thepaper from being greatly laurel.

[0036] Explanation will be hereinbelow made of a third embodiment of thepresent invention.

[0037] In the case of mounting the electronic circuit chip on a papersheet, when a force is exerted to the paper sheet from the outside dueto handling of the paper sheet, the force is also exerted to the papersheet when the paper sheet is curved. In this embodiment, if theelectronic circuit chip is planar (in a nearly rectangularparallelepiped), the electronic circuit chip which is designedsatisfying conditions having been previously obtained in order toprevent the electronic circuit chip from being broken by a forceexternally exerted is mounted on the paper sheet.

[0038] Referring to FIGS. 4a to 4 d, there are shown electronic circuitchips 41 and paper sheets 42, 43. FIGS. 4a and 4 c show an example inwhich the electronic circuit chip 41 is held between the sheets 42, 43which are bonded together, FIG. 4a illustrating a condition in which noforce is exerted to the paper sheet while FIG. 4c illustrates acondition in which a force is exerted to the paper sheet which istherefore curved. FIGS. 4b and 4 d show in an example in which theelectronic circuit chip 41 is bonded to the upper surface of the papersheet 43, FIG. 4b illustrating a condition in which no force is exertedthereto while FIG. 4d illustrates a condition in which a force isexerted thereto so that the paper sheet is curved.

[0039] When a force and a moment are exerted to the paper sheet so thatthe long sides of the planar surface of the electronic circuit chip arecurved, the force and the moment are effected in various positions onthe electronic circuits chip. Estimating that one of the short sides ofthe planar surface of the electronic circuit chip is set as a fixed endwhile the other side on the opposite side is set as a free end, theforce and the moment can be exhibited being substituted by the equallydistributed loads exerted over the entire area of the planar surface, aconcentrated load exerted to the free end, and a moment exerted to thefree end. Even in such a case that the electronic circuit chip is heldbetween the paper sheets, and also in such a case that it is bonded tothe upper surface of the paper sheet, it is approximated to a similarconfiguration.

[0040] Referring to FIG. 5 which is a view approximately exhibits aforce and a moment which are exerted so as to curve the electroniccircuit chip, a part indicated by rightward upward oblique linesexhibits a section of the electronic circuit chip 41, in parallel withthe long sides of the planer surface thereof. The short sides of theplanar surface of the electronic circuit chip 41 correspond to oppositeends of the section of the electronic circuit chip 41 in FIG. 4. Ofthese ends, the left end serves as the free ends while the right endserves as the fixed end. Referring to FIG. 4, the fixed part isexhibited by rightward downward oblique lines. Referring to this figure,there are shown a thickness H (m) of the electronic circuit chip 41, thelength L (m) of the long sides of the electronic circuit chip, equallydistributed loads P (N/m²) per unit area, which are exerted over theentire area of the planar surface of the electronic circuit chip 41, aconcentrated load W (N/m) per unit length, exerted to the free end, anda bending moment M (N) per unit length, exerted to the free end.

[0041] The forces P and W and the moment M with which the electroniccircuit chip 41 is curved, are estimated to be exerted within thesection thereof, and a positive force or moment is taken in a directionin which the electronic circuit chip 41 is curved downward. In thisembodiment the forces P and W and the moment M have positive values.

[0042] The x-axis is taken rightward from the free end as the origin. Amoment per unit length, exerted to a position x (m) by the equallydistributed loads P, is exhibited by Px²/2(N). A moment per unit length,exerted to a position x (m) by the concentrated load W is exhibited byWx (N). A moment per unit length exerted by the bending moment M isexhibited by a constant value M(N), independent from the value x.Accordingly, the total value M_(SUM) of the moments per unit length,exerted to the position x (m) is exhibited by Px²/2+Wx+M(N). x is takenin a range from o to L, and accordingly, M_(SUM) becomes maximum at x=L,thus,

M _(MAX) =PL ²/2+WL+M(N)

[0043] is obtained.

[0044] In this embodiment, since the shape of the electronic circuitchip can be approximated to a rectangular parallelepiped body, thebending stress exerted to the electronic circuit chip 41 becomes maximumat a position where the maximum bending moment is exerted, having avalue σ_(MAX) becomes 6M_(MAX)/H²(N/m²).

[0045] If the bending strength of the electronic circuit chip 41 isdenoted by σ(N/m₂), since a condition with which the electronic circuit41 can be prevented from being broken, is σ≧σ_(MAX),

3PL ²+6WL+6M−σH ²>0  (Formula 1)

[0046] is obtained.

[0047] By solving the equation for L, H, σ,

L>(−W+{W ² −PA)^(1/2) }/P  (Formula 2)

H≧{3(PL ²+2WL+2M)/σ}^(1/2)  (Formula 3)

σ≧(3PL ²+6WL+6M)/H ²  (Formula 4)

[0048] are obtained. In the formula 2, A is A=2M−σH²/3.

[0049] As a condition with which the electronic circuit chip isprevented from being broken, the maximum value of the length L (m) ofthe long sides is obtained from the formula 2, the minimum value of thethickness H (m) is obtained from the formula 3, and the minimum value ofthe bending strength σ(N/m²) is obtained from the formula 4.

[0050] In an example, in such a case that the electronic circuit chip ismounted between the paper sheets, having a thickness with which theelectronic circuit chip cannot be recognized even though the papersheets are externally touched, the maximum thickness H (m) of theelectronic circuit chip is determined. By substituting a bendingstrength σ(N/M²) which can be obtained from the material quality and theshape of the electronic circuit chip, the equally distributed loads P(N/m²) per unit area and the concentrated load W(N/m) per unit lengthwhich are expected to be applied when paper is used, and the moment M(N) per unit length, into the formula 2, the maximum long side length L(m) with which the electronic circuit chip can be prevented from beingbroken can be obtained.

[0051] In another example, in such a case that the electronic circuitchip should have multiple functions, since the scale of the circuitbecomes larger, the minimum value of the long side length L of theelectronic circuit chip is determined. By substituting a bendingstrength σ(N/m²), the equally distributed loads P (N m²) per unit area,and the concentrated load W(N/m) per unit length, and the moment M (N)per unit length, which are obtained similar to those as mentioned above,into the formula 3, the minimum thickness H (m) with which theelectronic circuit chip can be prevented from being broken, can beobtained.

[0052] Thus, according to this embodiment, it is possible to provide anelectronic circuit chip which can be prevented from being broken eventhough it is mounted to a soft material such as paper. Further, it ispossible to provide a sheet on to which the electronic circuit chipdesigned as mentioned above is mounted.

[0053] Next, explanation will be hereinbelow made of a forth embodimentof the present invention.

[0054] In this embodiment, a tape like sheet on which electronic circuitchips are mounted, is used.

[0055] Referring to FIG. 6, with the use of a tape-like sheet which canbe rolled up, not only separated sheets as shown in planar sheets, butalso a rolled continuous sheet can be provided.

[0056] A plurality of electronic circuit chips are mounted on anadhesive tape 61 at predetermined intervals. The adhesive tape isstocked in a rolled condition, and is used by being pulled by a requiredlength. Perforations 62 are formed in the adhesive tape 61 so that apaper piece on which a single electronic circuit chip is mounted can betaken out therefrom.

[0057] According this embodiment, even though no electronic circuit chiphas yet been mounted to a desired object, the electronic circuit partcan be mounted to the object by cutting off a piece on which a singleelectronic circuit chip is mounted and then by bonding the same to theobject.

[0058] According to this embodiment, an arbitrary object to which theadhesive tape 61 can be applied, can be mounted thereon with anarbitrary number of electronic circuit chips 41.

[0059] It is noted that although explanation has been made with the useof the adhesive tape 61 in this embodiment, a seal-like planer adhesivetape may be used, instead of the tape-like sheet.

[0060] Further, if a cut-off tape 61 can be applied to the object byanother means, it is not required that the tape is adhesive.

[0061] Further, the electronic circuit chips should not be limited toone and the same kind, but various kinds of electronic circuit chip canbe used.

[0062] Further, one and the same kind of electronic circuit chips 41 ora plural kinds of electronic circuit chips 41 may be cut off by a numberwhich is not only one but more.

INDUSTRIALLY USABILITY

[0063] As mentioned above, according to the present invention, anelectronic circuit chip can be mounted on a soft material such as paperwhile it can be prevented from being broken even though the material isbent or folded.

[0064] Further, according to the present invention, an electroniccircuit chip can be simply mounted on the material at an arbitraryposition.

1. A method of mounting a planar electronic circuit chip on a flexiblesheet together with another planer electric element, characterized bysteps of: selecting the another electric element and the electroniccircuit chip so that the planar surface of the another electric elementis greater than the planar surface of the electronic circuit chip; andmounting the another electric element and the electronic circuit chiponto the sheet so that the planer surface of the another electronicelement and the planar surface of the electronic circuit chip arelocated in parallel with the surface of the sheet, and the planersurface of the electronic circuit chip is accommodated within the planarsurface of the another electric element as viewed in a directionperpendicular to the surface of the sheet.
 2. A method of mounting anelectronic circuit chip onto a foldable sheet, characterized in that theelectronic circuit chip is mounted to the sheet so that the electroniccircuits chip is prevented from being located at a position where acrease is formed when the sheet is folded.
 3. A method of mounting acircuit chip on a foldable sheet having a rectangular sheet surface,characterized in that the electronic circuit chip is mounted on thesheet so as to prevent the electronic circuit chip from being located atleast at a position which is obtained by ½, ⅓ or ¼ of the length oflonger sides of the sheet surface and which is obtained by ½ of shortsides of the sheet surface.
 4. A method of mounting an electroniccircuit chip as set forth in claim 2, characterized in that theelectronic circuit chip is mounted at a position in the vicinity of anedge of the sheet surface.
 5. A method of mounting a planer electroniccircuit chip on a foldable sheet having a rectangular sheet surfacetogether with another planar electric element, characterized in thatsetting the planar surface of the another electric element to beslightly smaller than a size of each of rectangular area which areobtained by sectioning the sheet surface by n×m (where n and m areintegers larger than 2), and mounting the another electric element andthe electronic circuit chip on the sheet so that the planer surface ofthe another electric element and the planar surface of the electroniccircuit chip are arranged in parallel with the surface of the sheet, andthe planar surface of the another electric element is accommodatedwithin one of the rectangular areas which are obtained by sectioning thesheet surface with m×n, as viewed in a direction perpendicular to thesheet surface, and the planer surface of the electronic circuit chip isaccommodated within the planar surface of the another electric elementas viewed in a direction perpendicular to the sheet surface.
 6. A methodof mounting an electronic circuit chip as set forth in claim 2,characterized in that a long-rod like or a long planar like electricpart is mounted on the sheet so that the longitudinal direction of theelectric part is coincident with the sidewise direction of the sheet. 7.A method of mounting an electronic circuit chip as set forth in claim 2,characterized in that the sheet is made of paper.
 8. A method ofmounting an electronic circuit chip as set forth in claim 2,characterized in that the sheet is tape-like.
 9. A method of mounting anelectronic circuit chip as set forth in claim 7, characterized in thatthe sheet has a two layer structure, and the electronic circuit chip ismounted between two layers of the sheet.
 10. A method of mounting anelectronic circuit chip as set forth in claim 7, characterized in thatthe electronic circuit chip is mounted on the surface of one of twofront and rear sheet surfaces of the sheet.
 11. A planar electriccircuit chip mounted on a flexible sheet, characterized in that theelectronic circuit chip has a thickness, a length of the long sidesthereof, and a bending strength which satisfy: 3PL ²+6WL+6M−σH ²>0 wherea force exerted to the electronic circuit chip is exhibited by equallydistributed loads P (N/m²) per unit area, exerted to the entire planarsurface of the electronic circuit chip, and a concentrated load W (N/m)per unit length, is exerted to the free end, in such a case that one ofthe short sides of the planar surface of the electronic circuit chip isused as a fixed end while the other short side on the opposite sidethereof is used as a free end, where a moment exerted to the electroniccircuit chip is exhibited by a moment M (N) per unit length, exerted tothe free end in such a case that one of the short sides of the planarsurface of the electronic circuit chip is used as a fixed end while theother short side on the opposite side thereof is used as a free end, andwhere H (m) is the thickness of the electronic circuit chip; L (m) is alength of the long sides of the electronic circuit chip; and σ(N/m²) isa bending strength of stronger one of a bending strength of the planaranother electric element larger than the electronic circuit chip mountedon the planar surface of the another electric element and the bendingstrength of the electronic circuit chip.
 12. A sheet mounted thereonwith an electronic circuit chip stated in claim
 11. 13. A foldable sheethaving a rectangular sheet surface and mounted thereon with an electriccircuit composed of a planar electric circuit chip, a planar capacitorand an antenna, characterized in that the electronic circuit chip ismounted on the sheet so that it is prevented from being located at aposition where a crease is created when the sheet is folded in apredetermined folding method, and the another electric element and theelectronic circuit chip are mounted on the sheet so that the planarsurface of the another electric element and the planar surface of theelectronic circuit chip are in parallel with the sheet surface, theplanar surface of the electronic circuit chip is accommodated within theplanar surface of the another electric element, as viewed in a directionperpendicular to the surface of the sheet, and the antenna is mounted onthe sheet so that the longitudinal direction of the antenna iscoincident with the sidewise direction of the sheet.
 14. A foldablesheet having a rectangular sheet surface, and mounted thereon with anelectric circuit having a planar electronic circuit chip, a planarcapacitor and an antenna, characterized in that the planar surface ofthe capacitor has a size which is slightly smaller than that of each ofrectangular areas which are obtained by sectioning the sheet surfacewith n×m (where n and m are integers larger than 2), and the capacitor,the electronic circuit chip and the antenna are mounted on the sheet sothat the planar surface of the capacitor and the planar surface of thecapacitor are in parallel with the sheet surface, the planar surface ofthe capacitor is accommodated with one of the rectangular areas-obtainedby sectioning the sheet surface with n×m, as viewed in a directionperpendicular to the sheet surface, and the planar surface of theelectronic circuit part and the contour of the antenna are accommodatedwithin the planar surface of the capacitor as viewed in a directionperpendicular to the sheet surface.